When using non-Nikon crop lenses, Auto DX will not switch to DX mode. Only when using Nikon DX lenses will Nikon FX cameras switch to DX crop mode when Auto DX is set to ON.
When using non-Nikon crop lenses, Auto DX will not switch to DX mode. Only when using Nikon DX lenses will Nikon FX cameras switch to DX crop mode when Auto DX is set to ON.